Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element
Patent Information
- Application Number
- KR1020237040562
- Authority / Receiving Office
- KR · KR
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2021-05-06
- Filing Date
- 2022-04-28
- Publication Date
- 2026-09-21
- Estimated Expiration
- 2042-04-28
Smart Images
Figure 112023131398127-PCT00027_ABST
Abstract
Description
Technology Field
[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. Background Technology
[0002] A liquid crystal display device is constructed by clamping a liquid crystal layer between a pair of transparent substrates equipped with electrodes. In the liquid crystal display device, an organic film made of an organic material is used as a liquid crystal alignment layer so that the liquid crystal is aligned to a desired orientation state between the substrates. That is, the liquid crystal alignment layer is formed on the surface of the substrate that clamps the liquid crystal and contacts the liquid crystal, and plays the role of aligning the liquid crystal in a certain direction between the substrates. Furthermore, the pretilt angle of the liquid crystal can be controlled by the liquid crystal alignment layer. Methods such as lowering the pretilt angle by mainly selecting a polyimide structure (see Patent Documents 1 and 2) are known.
[0003] Recently, with the increase in performance of liquid crystal display devices, liquid crystal display devices are being used for automotive applications, such as car navigation systems, meter panels, surveillance cameras, and medical camera monitors, in addition to applications such as large-screen, high-definition liquid crystal televisions. Due to the demand for viewing angle characteristics, among the driving methods of liquid crystal molecules, the IPS method and FFS method, which have excellent viewing angle characteristics, are being considered, and polyimide-based liquid crystal alignment films are being proposed as rubbing alignment films (see Patent Document 3).
[0004] In addition, in liquid crystal display devices of the IPS and FFS types, static electricity tends to accumulate within the liquid crystal cell, and these accumulated charges affect the display as disturbances in liquid crystal alignment or afterimages, significantly degrading the display quality of the liquid crystal display device. Therefore, a liquid crystal alignment film is required that can reduce the generated charge in a short time and also reduce the absolute value of the accumulated charge. In solving these problems, Patent Document 4 proposes a liquid crystal alignment agent containing a polyamic acid or polyimide having a structural unit having an aromatic tetracarboxylic acid residue and a structural unit having a dicyclic tetracarboxylic acid residue, and Patent Document 5 proposes a liquid crystal alignment agent containing a polyimide precursor having a diphenylamine backbone.
[0005] In addition, recently, flexible liquid crystal devices using PET film or polycarbonate film as a substrate are being considered in terms of enhancing design, and liquid crystal alignment film materials suitable for a low-temperature firing process in which the firing temperature of the substrate when forming the liquid crystal alignment film is less than 200 ℃ have been proposed (see Patent Document 6). Prior art literature
[0006] Japanese Patent Publication No. Hei 9-188761, Japanese Patent Publication No. Hei 10-123532, International Publication No. 2019-082975, International Publication No. 02-033481, International Publication No. 2014-010402, International Publication No. 2018-124167 The problem to be solved
[0007] In liquid crystal display devices using a horizontal electric field method such as IPS driving method or FFS driving method, positive liquid crystals were conventionally used, but since it is possible to reduce transmission loss at the electrode top and improve contrast by using negative liquid crystals, liquid crystal display devices using negative liquid crystals are being considered recently.
[0008] However, as a result of the inventors of the present invention, it was found that if a negative type liquid crystal is used as a liquid crystal material, the occurrence rate of display defects (line burn-in) is high, and thus it is not possible to obtain a liquid crystal display element with excellent display quality.
[0009] In addition, for IPS and FFS type liquid crystal cells, if the stability of liquid crystal alignment is low, the liquid crystal does not return to its initial state when driven for a long time, causing a decrease in contrast or afterimages; therefore, the stability of liquid crystal alignment is important. Furthermore, in recent high-brightness liquid crystal display devices, the brightness of the backlight is high and the visibility of afterimages caused by accumulated charge is also high. Thus, a liquid crystal alignment film is required that can reduce the generated charge in a short time while reducing the absolute value of the accumulated charge more than in the past.
[0010] Meanwhile, in order to address the aforementioned display defects or low-temperature firing process, a liquid crystal alignment agent was examined in which an epoxy compound having a tertiary amine structure was added to polyimide as described in Patent Document 6. As a result, it was found that the polyimide film was prone to peeling during the alignment process, and it became difficult to solve all these problems with the prior art.
[0011] The objective of the present invention is to provide a liquid crystal alignment agent that, taking into account the above circumstances, obtains a liquid crystal display device with a low occurrence rate of display defects (line burn-in) even when a negative-type liquid crystal is used as the liquid crystal material. Furthermore, the invention aims to provide a liquid crystal alignment agent that obtains a liquid crystal alignment film capable of reducing generated charge in a short time while reducing the absolute value of accumulated charge and having high stability of liquid crystal alignment. Additionally, the invention aims to provide a liquid crystal alignment agent that obtains a liquid crystal alignment film in which film erosion during alignment treatment is suppressed in a low-temperature firing process of 200°C or lower.
[0012] As a result of repeated examinations to achieve the above objective, the inventors discovered that a liquid crystal alignment agent with the following composition is optimal for achieving the above objective, and thus completed the present invention. means of solving the problem
[0013] Thus, the present invention is based on the above-mentioned findings and has the following gist.
[0014] A liquid crystal orientation agent characterized by containing the following polymer (A), polymer (B) and crosslinkable compound (C).
[0015] Polymer (A): a diamine represented by the following formula (d0) and the following formula (d D A polyimide obtained by imidizing a polyimide precursor, which is a reaction product of a diamine component containing a diamine represented by ) and a tetracarboxylic acid derivative component.
[0016] Polymer (B): "HN(R)-Y D' -N(R)-H」(Y D' represents a divalent organic group having a group "-N(D')-" (D' represents a protecting group that is detached by heating and replaced by a hydrogen atom) within the molecule. R is of the formula (d D It has the same meaning as R of ).) Diamine represented as (d D'B ) and the following expression (d B Diamine represented by ) (wherein diamine (d D'B A polyimide precursor that is a reaction product of a diamine component and a tetracarboxylic acid derivative component, comprising (excluding ). However, the polyimide precursor does not have an imide ring structure.
[0017] Crosslinkable compound (C): Formula below (E n Epoxy compounds represented by ).
[0018] [Chemical Formula 1]
[0019]
[0020] (In formula (d0), the two Ars each independently represent a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom on the ring may be substituted with a monovalent group.)
[0021] L o -O-(-Ar'-O-) n - (n is an integer from 0 to 3. Ar' represents a divalent benzene ring or a biphenyl structure, and any hydrogen atom on the ring may be substituted with a monovalent group. If there are multiple Ar' groups, the multiple Ar' groups may be identical or different.), -(CH2) n - (n is an integer from 2 to 18), or that -(CH2) n - Represents a group in which at least a portion of the -CH2- is substituted with any of -O-, -C(=O)- or -OC(=O)-.
[0022] Equation (d D ) Among, Y D represents a divalent organic group having a group "-N(D)-" (D represents a protecting group that is detached by heating and replaced by a hydrogen atom) within the molecule.
[0023] Equation (d0) and Equation (d D Among ), multiple Rs each independently represent a hydrogen atom or a monovalent organic group.
[0024] [Chemical Formula 2]
[0025]
[0026] (Y B represents a divalent organic group satisfying the following conditions (1) and (2). R has the same meaning as R in the above formula (d0).
[0027] Condition (1): It does not have a nitrogen atom-containing structure selected from the group consisting of a complex ring containing a nitrogen atom and a secondary or tertiary amino group (except for an amino group derived from the group “-N(D’)-” (D’ represents a protecting group that is removed by heating and replaced by a hydrogen atom).
[0028] Condition (2): Does not have a side chain with 6 or more carbon atoms.
[0029] [Chemical Formula 3]
[0030]
[0031] (a is an integer from 2 to 4, and R a is an organic group of a, and the bonding sites with a number of N atoms are aliphatic carbon atoms.
[0032] In addition, in this specification, Boc represents a tert-butoxycarbonyl group. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. The imidation rate referred to in this specification is the ratio of the imide group to the total amount of the imide group and the carboxyl group (or its derivative) derived from the tetracarboxylic acid dihydride or its derivative. Effects of the invention
[0033] By using the liquid crystal alignment agent of the present invention, a liquid crystal display device is obtained that has a low occurrence rate of display defects (line burn-in) even when a negative-type liquid crystal is used as the liquid crystal material. In addition, a liquid crystal alignment film is obtained that has high stability of liquid crystal alignment and can reduce the generated charge in a short time while reducing the absolute value of the accumulated charge. Furthermore, in a low-temperature firing process of 200°C or lower, a liquid crystal alignment film is obtained in which film erosion during alignment treatment is suppressed, thereby obtaining a liquid crystal display device with excellent display quality. Specific details for implementing the invention
[0034] <Polymer (A)>
[0035] The liquid crystal alignment agent of the present invention comprises a diamine represented by the formula (d0) and the formula (d D It contains a polyimide polymer (A) obtained by imidizing a polyimide precursor, which is a reaction product of a diamine component containing a diamine represented by ) and a tetracarboxylic acid derivative component. By adopting the above embodiment, high-temperature treatment required for thermal imidization becomes unnecessary. In addition, because it contains a specific diamine component, the resulting liquid crystal alignment film has high stability of liquid crystal alignment and a low occurrence rate of display defects (line burn-in), thereby obtaining a liquid crystal display device.
[0036] The above polymer (A) is obtained by imidizing a polyimide precursor obtained from a tetracarboxylic acid derivative component containing tetracarboxylic acid dihydride and a diamine component containing a specific diamine. The imidization rate of the polyimide in the polymer (A) is preferably 10 to 100% from the perspective of lowering the occurrence rate of display defects. In addition, the lower limit of the imidization rate is preferably 10%, more preferably 20%, even more preferably 50%, and most preferably 70%, and the upper limit of the imidization rate is preferably 100%, more preferably 99%, and even more preferably 95%. Below, specific examples of materials used in the manufacture of the polymer (A) and the manufacturing method are described in detail.
[0037] The diamine component used in the preparation of the polyimide polymer (A) contained in the liquid crystal alignment agent of the present invention is a diamine represented by the following formula (d0) and the following formula (d D It contains a diamine represented by ). A diamine represented by the following formula (d0) and the following formula (d D The diamines represented by ) may each be used as a single type or in combination of two or more types.
[0038] [Chemical Formula 4]
[0039]
[0040] (The definition of each symbol in the formula is the same as above.)
[0041] Ar and L in the above equation (d0) o The hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring having Ar' included in is, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms (more preferably 1 to 5 carbon atoms), an alkenyl group having 2 to 10 carbon atoms (more preferably 2 to 5 carbon atoms), an alkoxy group having 1 to 10 carbon atoms (more preferably 1 to 5 carbon atoms), a fluoroalkyl group having 1 to 10 carbon atoms (more preferably 1 to 5 carbon atoms), a fluoroalkenyl group having 2 to 10 carbon atoms (more preferably 2 to 5 carbon atoms), a fluoroalkoxy group having 1 to 10 carbon atoms (more preferably 1 to 5 carbon atoms), a hydroxyl group, an alkyloxycarbonyl group having 1 to 10 carbon atoms (more preferably 1 to 5 carbon atoms), a cyano group, It may be replaced with nitro groups, etc.
[0042] The diamine represented by the above formula (d0) is 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, compounds represented by the following formulas (d0-1) to (d0-10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, At least one diamine selected from the group consisting of 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine.
[0043] [Chemical Formula 5]
[0044]
[0045] The above equation (d D The diamine represented by ) is, in view to preferably obtain the effects of the present invention, an aromatic diamine having one aromatic ring in the molecule, wherein at least one of any hydrogen atoms on the aromatic ring is substituted with a monovalent group having the group "-N(D)-" (d n1), or an aromatic diamine having two aromatic rings within the molecule, wherein the two aromatic rings are single bonds, -CH2-, -C(CH3)2-, -O-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D"), -NR- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D"), an alkylene group having 2 to 20 carbon atoms, and any -CH2- of the alkylene group is -O-, -Si(CH3)2-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D") or a divalent group selected from the group consisting of a divalent group substituted with -NR- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D") (L n As an aromatic diamine connected by ), (i) any hydrogen atom on the aromatic ring is substituted with a monovalent group having "-N(D)-", or (ii) said divalent group (L n ) An aromatic diamine satisfying at least one of the conditions having this group "-N(D)-" (d n2 Examples of the above aromatic rings include, for instance, benzene rings, naphthalene rings, and anthracene rings, benzene rings and naphthalene rings are preferred, and benzene rings are more preferred. Additionally, any hydrogen atom on the above aromatic ring may be substituted with a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a carboxyl group, a halogen atom, a monovalent organic group having 1 to 5 carbon atoms containing a fluorine atom, or a monovalent organic group in which a portion of the hydrogen atom on the alkyl group having 1 to 5 carbon atoms is substituted with a hydroxyl group.
[0046] D in the group "-N(D)-" represents a protecting group that is detached by heating and replaced by a hydrogen atom, and is not particularly limited as long as it is an organic group that is converted to the group "-NH-" by decomposing and detaching by heat. Examples of structures for D, which is an organic group that can be detached by heat, include carbamate-type organic groups such as benzyloxycarbonyl groups, 9-fluorenylmethyloxycarbonyl groups, allyloxycarbonyl groups, and tert-butoxycarbonyl groups; however, tert-butoxycarbonyl groups are particularly preferred from the perspective that the efficiency of detachment by heat is good, detachment occurs at a relatively low temperature, and it is discharged as a harmless gas when detached.
[0047] The above equation (d D A diamine represented by ) is, the following formula (d D -1) ∼ (d D A diamine selected from -7) is preferred.
[0048] [Chemical Formula 6]
[0049]
[0050] (Equation (d D -2), equation (d D -6) and equation (d D -7) In this case, R represents a hydrogen atom or a tert-butoxycarbonyl group.)
[0051] The preferred content of the diamine represented by the above formula (d0) is preferably 50 to 95 mol% with respect to the total component of the diamine component used in the manufacture of the polymer (A), and more preferably 50 to 90 mol%.
[0052] The above equation (d D The preferred content of the diamine is preferably 5 to 50 mol% with respect to the total component of the diamine component used in the manufacture of the polymer (A), and more preferably 10 to 50 mol%.
[0053] The diamine component used in the preparation of the polymer (A) contained in the liquid crystal alignment agent of the present invention may include various diamines (hereinafter also referred to as other diamine 1) in addition to the diamine described above, depending on the characteristics of the liquid crystal alignment agent obtained. Each of the other diamine 1 may be used alone or in combination of two or more types.
[0054] Other diamines include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-Difluoro-4,4'-Diaminobiphenyl, 3,3'-Difluoro-4,4'-Diaminobiphenyl, 2,2'-Bis(trifluoromethyl)-4,4'-Diaminobiphenyl, 3,3'-Bis(trifluoromethyl)-4,4'-Diaminobiphenyl, 3,4'-Diaminobiphenyl, 4,4'-Diaminobiphenyl, 3,3'-Diaminobiphenyl, 2,2'-Diaminobiphenyl, 2,3'-Diaminobiphenyl, 1,5-Diaminonaphthalene, 1,6-Diaminonaphthalene, 1,7-Diaminonaphthalene, 2,5-Diaminonaphthalene, 2,6-Diaminonaphthalene, 2,7-Diaminonaphthalene, 3,3'-Diaminodiphenylmethane, 3,4'-Diaminodiphenylmethane, 4,4'-Diaminodiphenylmethane, 4,4'-Sulfonyldianiline, 3,3'-Sulfonyldianiline, Bis(4-aminophenyl)silane, Bis(3-aminophenyl)silane, Dimethyl-Bis(4-aminophenyl)silane, Dimethyl-Bis(3-aminophenyl)silane, 4,4'-Thiodianiline, 3,3'-Thiodianiline, 1,4-Bis(4-aminophenyl)benzene, 1,3-Bis(4-aminophenyl)benzene, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), Bis(4-aminophenyl)terephthalate, Bis(3-aminophenyl)terephthalate, Bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; diamine having a photooriented group such as 4,4'-diaminoazobenzene or diaminotolan;Diamines having a photopolymerizable group at the terminal end, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallyaniline; diamines having a radical polymerization initiator function, such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines having an amide link, such as 4,4'-diaminobenzanilide; diamines having a urea link, such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,3-bis(4-aminophenethyl)urea; 2,2'-Bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-Bis(4-aminophenyl)hexafluoropropane, 2,2'-Bis(3-aminophenyl)hexafluoropropane, 2,2'-Bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-Bis(4-aminophenyl)propane, 2,2'-Bis(3-aminophenyl)propane, 2,2'-Bis(3-amino-4-methylphenyl)propane, 4,4'-Diaminobenzophenone, 1,4-Bis(4-aminobenzyl)benzene ;2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimizine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazole-1-yl)propyl-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, or heterocyclic diamines such as diamines represented by the following formulas (z-1) to (z-13), or, 4,4'-diaminodiphenylamine, A diamine having at least one nitrogen atom-containing structure selected from the group consisting of a heterocyclic ring containing a nitrogen atom and a secondary or tertiary amino group, represented by a diamine having a diphenylamine structure such as 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine (provided, an amino group derived from the group "-N(D)-" (D represents a protecting group that is detached by heating and substituted with a hydrogen atom). Hereinafter also referred to as a specific nitrogen atom-containing structure); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-Diaminoresorcinol, 4,4'-Diamino-3,3'-Dihydroxybiphenyl;2,4-diamino-benzoic acid, 2,5-diamino-benzoic acid, 3,5-diamino-benzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, Diamines having a carboxyl group such as 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; diamines having a steroid backbone such as cholestanyloxy-3,5-diaminobenzene, cholestenioxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, 3,5-diaminobenzoate cholestanyl, 3,5-diaminobenzoate cholestenyl, 3,5-diaminobenzoate lanostanyl, and 3,6-bis(4-aminobenzoyloxy)cholestan; diamines represented by the following formulas (V-1) to (V-2); Examples include diamines having siloxane bonds such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; acyclic aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine); and diamines in which two amino groups are bonded to a group represented by any of formulas (Y-1) to (Y-167) described in International Publication No. 2018 / 117239.
[0055] [Chemical Formula 7]
[0056]
[0057] [Chemical Formula 8]
[0058]
[0059] [Chemical Formula 9]
[0060]
[0061] (In Equation (V-1), m and n are integers from 1 to 3 (provided that 1 ≤ m + n ≤ 4), j is an integer of 0 or 1, and X 1 은, -(CH2) a - (a is an integer from 1 to 15), representing -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-, and R 1 It represents a fluorine atom, an alkyl group containing a fluorine atom having 1 to 10 carbon atoms, an alkoxy group containing a fluorine atom having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms.
[0062] In equation (V-2), X 2 represents -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. R 2 represents a fluorine atom-containing alkyl group having 1 to 20 carbon atoms, or an alkyl group having 3 to 20 carbon atoms.
[0063] Among the above formulas, m, n, X 1 , R 1 If these two exist, each has the above definition independently.)
[0064] The above equations (d0) and (d D When using other diamine 1 in addition to the diamine of ), the amount of other diamine 1 used is preferably 5 to 40 mol% and more preferably 10 to 40 mol% with respect to the total diamine component used in the preparation of polymer (A). Also, the formula (d0) and (d DThe total content of the diamines is preferably 95 mol% or less with respect to the total diamine components used in the manufacture of polymer (A), and preferably 90 mol% or less.
[0065] <Tetracarboxylic acid derivatives>
[0066] The tetracarboxylic acid derivative component used in the preparation of the polymer (A) of the present invention may include not only tetracarboxylic acid dihydride but also derivatives thereof such as tetracarboxylic acid dihalide compounds, tetracarboxylic acid dialkyl esters, tetracarboxylic acid dialkyl ester dihalides, etc. The tetracarboxylic acid derivative component may use one type of tetracarboxylic acid dihydride or its derivative alone, or two or more types may be used in combination.
[0067] Specific examples of the above tetracarboxylic acid dihydride or derivatives include acyclic aliphatic tetracarboxylic acid dihydride, alicyclic tetracarboxylic acid dihydride, aromatic tetracarboxylic acid dihydride, or derivatives thereof. Among these, from the viewpoint of obtaining the effects of the present invention in a desirable manner, it is more preferable to contain a tetracarboxylic acid dihydride or derivatives thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure (hereinafter collectively referred to as tetracarboxylic acid derivatives having a specific partial structure), and it is even more preferable to contain a tetracarboxylic acid dihydride or derivatives thereof having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure.
[0068] In addition, aromatic tetracarboxylic acid dihydrides are acid dihydrides obtained by including at least one carboxyl group bonded to an aromatic ring and dehydrating four carboxyl groups within the molecule.
[0069] A cyclic aliphatic tetracarboxylic acid dihydride is an acid dihydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, it does not need to be composed solely of a chain hydrocarbon structure, and may have an alicyclic structure or an aromatic ring structure in part.
[0070] A dihydrogenated alicyclic tetracarboxylic acid is an acid dihydrogen obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. In addition, it is not necessary to be composed solely of alicyclic structures, and it may have a chain-type hydrocarbon structure or an aromatic ring structure in part.
[0071] The tetracarboxylic acid derivative component that can be used in the synthesis of the above polymer (A) preferably includes the following tetracarboxylic acid dihydride or its derivative (hereinafter collectively referred to as specific tetracarboxylic acid derivatives).
[0072] Acyclic aliphatic tetracarboxylic acid dihydrides such as 1,2,3,4-butanetetracarboxylic acid dihydride; 1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid 2 anhydride, 1,2,3,4-cyclopentanetetracarboxylic acid 2 anhydride, 1,2,4,5-cyclohexanedetatecarboxylic acid dihydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dihydride, 2,3,5-tricarboxycyclopentylacetic acid dihydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid dihydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, Bicyclo[2.2.2]octa-7-en-2,3,5,6-tetracarboxylic acid 2 anhydride, bicyclo[2.2.2]octa-2,3,5,6-tetracarboxylic acid 2 anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]Alicyclic tetracarboxylic acid dihydrogen such as octane-2:4,6:8-2 anhydrous; Pyromellitic acid 2 anhydride, 3,3',4,4'-benzophenone tetracarboxylic acid 2 anhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic acid 2 anhydride, 1,4,5,8-naphthalene tetracarboxylic acid 2 anhydride, 2,3,6,7-naphthalene tetracarboxylic acid 2 anhydride, 3,3',4,4'-biphenyl ether tetracarboxylic acid 2 anhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid 2 anhydride, 3,3',4,4'-biphenyl tetracarboxylic acid 2 anhydride, 2,2',3,3'-biphenyl tetracarboxylic acid 2 anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane 2 anhydride, Aromatic tetracarboxylic acid dihydrides such as ethylene glycol bis-anhydrotrimate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic acid) dihydride, or 4,4'-methylenedi(1,4-phenylene)bis(phthalic acid) dihydride; and other tetracarboxylic acid dihydrides described in Japanese Patent Publication No. 2010-97188, etc.
[0073] More preferred examples of the specific tetracarboxylic acid derivatives mentioned above include 1,2,3,4-butanetetracarboxylic acid dihydride, 1,2,3,4-cyclobutanetetracarboxylic acid dihydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dihydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dihydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dihydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dihydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dihydride, and 1,2,3,4-cyclopentanetetracarboxylic acid 2 Anhydride, 1,2,4,5-cyclohexanedetatecarboxylic acid dihydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dihydride, 2,3,5-tricarboxycyclopentylacetic acid dihydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2hydride, pyromellitic acid dihydride, 3,3',4,4'-benzophenone tetracarboxylic acid dihydride, 3,3',4,4'-biphenylsulfone tetracarboxylic acid dihydride, 1,4,5,8-naphthalene tetracarboxylic acid dihydride, 2,3,6,7-naphthalene tetracarboxylic acid dihydride, 3,3',4,4'-biphenyl ether tetracarboxylic acid dihydride, 3,3',4,4'-biphenyl tetracarboxylic acid dihydride, 2,2',3,3'-biphenyl tetracarboxylic acid dihydride, or derivatives thereof.
[0074] The usage ratio of the tetracarboxylic acid derivative having the above-mentioned specific partial structure or the specific tetracarboxylic acid derivative is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more with respect to the total tetracarboxylic acid derivative component used.
[0075] <Polymer (B)>
[0076] The liquid crystal alignment agent of the present invention is “HN(R)-Y D' -N(R)-H」(Y D' represents a divalent organic group having a group "-N(D')-" (D' represents a protecting group that is detached by heating and replaced by a hydrogen atom) within the molecule. R is of the formula (d D It has the same meaning as R of ).) Diamine represented as (d D'B ) and the above equation (d B Diamine represented by ) (wherein diamine (d D'B It contains a polymer (B) which is a polyimide precursor that is a reaction product of a diamine component composed of (excluding ) and a tetracarboxylic acid derivative component. However, the polyimide precursor of the polymer (B) does not have an imide ring structure.
[0077] In the diamine component used in the manufacture of polymer (B), the diamine (d D'B By including ), it becomes possible to localize the polymer (B) in the polyimide layer derived from the polymer (A) when used as a liquid crystal alignment film. Therefore, the film strength improvement effect of the polymer (B) is enhanced, and the erosion of the film during alignment treatment is suppressed.
[0078] Also, the diamine component used in the manufacture of the polymer (B) is of the above formula (d B It contains a diamine represented by ). Here, the diamine (d B Divalent organic group Y contained in ) B ... satisfies the above conditions (1) and (2).
[0079] By adopting the embodiment of condition (1), the basicity of the polymer is reduced and the thermoimide reaction of the polymer (B) is suppressed, making it possible to obtain a liquid crystal alignment film with high film strength. Also, by adopting the embodiment of condition (2), the alignment control power of the liquid crystal in the IPS method and FFS method is increased, making it possible to increase the alignment stability of the obtained liquid crystal alignment film.
[0080] Here, a divalent organic group having a nitrogen atom-containing structure selected from the group consisting of a heterocyclic ring containing a nitrogen atom and a secondary or tertiary amino group (excluding amino groups derived from the group "-N(D')-"), wherein the group "-NHR" (R is the above formula (d B (It has the same meaning as R in ) As a diamine formed by the bonding of these two groups, examples include diamines having a specific nitrogen atom-containing structure as exemplified in other diamines 1 of the polymer (A).
[0081] The above equation (d B The diamines represented by ) preferably include an aromatic diamine (I) having one benzene ring; a diamine (II-a) having two benzene rings connected by a single bond; and an aromatic diamine (II-b) in which two benzene rings are connected by a divalent group, wherein the divalent group is an oxygen atom or an organic group having 1 to 3 carbon atoms and is bonded to the same atom as the two benzene rings. However, the aromatic diamine (I), aromatic diamine (II-a), and aromatic diamine (II-b) are the above diamines (d D'B As a diamine other than ), it satisfies the above conditions (1) and (2).
[0082] The above equation (d B A more preferred specific example of the diamine represented by ) is the formula (d described below). MDiamines represented by ), compounds represented by the formulas (d0-1) to (d0-10), 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-phenylenebis(4-aminobenzoate), Examples include 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, diamine having the photooriented group, diamine having the amide bond, diamine having the urea bond, or 1,4-bis(4-aminobenzyl)benzene.
[0083] The above diamine (d D'B Specific examples of ) include the diamine (d) by including a preferred embodiment. D Examples include the diamines exemplified in ). The above diamine (d D'B ) may use 1 type alone, or 2 or more types in combination.
[0084] In addition, specific examples of D' of the "-N(D')-" include the structure exemplified in D of the "-N(D)-" above, which includes a preferred embodiment.
[0085] The above equation (d D'B The preferred content of the diamine is preferably 5 to 40 mol% with respect to the total diamine component of the diamine component used in the manufacture of the polymer (B), and more preferably 10 to 40 mol%.
[0086] The diamine component used in the manufacture of polymer (B) is, in order to preferably obtain the effects of the present invention, of the following formula (d M It is desirable to contain a diamine represented by ).
[0087] [Chemical Formula 10]
[0088]
[0089] (L M represents a single bond, -CH2-, -CO-, -O-, or -C(CH3)2-. L M ' is, single bond or -(CH2) m - Represents (m is an integer from 1 to 2). Ar M Silver represents a divalent benzene ring, and any hydrogen atom on the ring may be replaced with a monovalent group. Ar M If this plural exists, the plural Ar M may be identical or different. Multiple Rs each independently represent a hydrogen atom or a monovalent organic group. n is an integer from 0 to 1.)
[0090] Ar M The hydrogen atoms on the benzene ring may be substituted with a halogen atom, a C1-5 alkyl group, a C2-5 alkenyl group, a C1-5 alkoxy group, a C1-5 fluoroalkyl group, a C2-5 fluoroalkenyl group, a C1-5 fluoroalkoxy group, a hydroxyl group, an C1-5 alkyloxycarbonyl group, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, etc.
[0091] The above equation (d MAs a preferred embodiment of the diamine represented by ), p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 3-aminobenzylamine, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-Dihydroxy-4,4'-Diaminobiphenyl, 2,2'-Difluoro-4,4'-Diaminobiphenyl, 3,3'-Difluoro-4,4'-Diaminobiphenyl, 2,2'-Ditrifluoromethyl 4,4'-Diaminobiphenyl, 3,3'-Bis(trifluoromethyl)-4,4'-Diaminobiphenyl, 3,4'-Diaminobiphenyl, 4,4'-Diaminobiphenyl, 3,3'-Diaminobiphenyl, 2,2'-Diaminobiphenyl, 2,3'-Diaminobiphenyl, 3,3'-Diaminodiphenylmethane, 3,4'-Diaminodiphenylmethane, 4,4'-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-Diaminodiphenylmethane, 2,2'-Bis(4-aminophenyl)propane, Examples include 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, and other diamines having the above-mentioned carboxyl group as described in Diamine 1. Among these, p-phenylenediamine, m-phenylenediamine, 3-aminobenzylamine, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, and 4,4'-diaminodiphenyl ether are more preferred.
[0092] The above diamine (d M) may use 1 type alone, or 2 or more types in combination.
[0093] The above equation (d M The preferred content of the diamine is preferably 60 to 95 mol% of the total diamine component of the diamine component used in the manufacture of the polymer (B), and more preferably 60 to 90 mol%.
[0094] The diamine component used in the manufacture of the polymer (B) is the above diamine (d D'B ) and diamine (d M A diamine other than ) (hereinafter also referred to as other diamine 2) may be used. A specific example of other diamine 2 is a diamine that satisfies the above conditions (1) and (2) as a diamine component for obtaining the above polymer (A).
[0095] Specific examples of the tetracarboxylic acid derivative component used in the manufacture of the above polymer (B) may include compounds identical to the compounds exemplified in polymer (A), including preferred embodiments. The tetracarboxylic acid derivative component used in the manufacture of polymer (B) is more preferably a tetracarboxylic acid derivative having the specific partial structure or a specific tetracarboxylic acid derivative, and most preferably a more preferred embodiment of the specific tetracarboxylic acid derivative. Furthermore, it is preferable to contain at least 10 mol% of the tetracarboxylic acid derivative having the specific partial structure or the specific tetracarboxylic acid derivative with respect to the total tetracarboxylic acid derivative component used in the manufacture of polymer (B), more preferably at least 20 mol%, and even more preferably at least 50 mol%.
[0096] In addition, from the perspective of obtaining a liquid crystal alignment film capable of reducing the generated charge in a short time while reducing the absolute value of the accumulated charge, the tetracarboxylic acid derivative component used in the manufacture of the polymer (B) preferably contains the aromatic tetracarboxylic acid dihydride or its derivative, and among them, the tetracarboxylic acid dihydride or its derivative having a benzene ring structure is preferred. More preferably, it is the aromatic tetracarboxylic acid dihydride or its derivative exemplified in the specific tetracarboxylic acid derivative.
[0097] The tetracarboxylic acid derivative component used in the manufacture of polymer (A) and the tetracarboxylic acid derivative component used in the manufacture of polymer (B) may be the same or different.
[0098] In order to obtain the effects of the present invention in a desirable manner, the content ratio of polymer (A) and polymer (B) is preferably 10 / 90 to 90 / 10 in mass ratio of [polymer (A)] / [polymer (B)], more preferably 20 / 80 to 90 / 10, and even more preferably 20 / 80 to 80 / 20.
[0099] <Method for manufacturing polymer (A) and polymer (B)>
[0100] Polyimide precursors, such as polyamic acid or polyamic acid esters, used in the manufacture of polymer (A) and polymer (B) contained in the liquid crystal orientation agent of the present invention can be synthesized, for example, by the following method.
[0101] (Synthesis of polyamic acid)
[0102] The synthesis of polyamic acid is carried out by reacting a diamine component containing the above diamine with a tetracarboxylic acid derivative component containing the above tetracarboxylic acid dihydride or its derivative in an organic solvent. The ratio of tetracarboxylic acid dihydride and diamine used in the synthesis reaction of polyamic acid is preferably such that the acid anhydride group of tetracarboxylic acid dihydride is 0.5 to 2 equivalents relative to 1 equivalent of the amino group of the diamine, and more preferably such that the acid anhydride group is 0.8 to 1.2 equivalents. As with conventional polycondensation reactions, the closer the equivalent of the acid anhydride group of the tetracarboxylic acid dihydride is to 1 equivalent, the larger the molecular weight of the polyamic acid produced.
[0103] In the synthesis reaction of polyamic acid, the reaction temperature is preferably -20 to 150 ℃, and more preferably 0 to 100 ℃. In addition, the reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours.
[0104] The synthesis reaction of polyamic acid can be carried out at any concentration, but preferably 1 to 50 mass%, more preferably 5 to 30 mass%. The reaction may be carried out at a high concentration initially, and then a solvent may be added.
[0105] Specific examples of the above organic solvents include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether may be used.
[0106] (Synthesis of polyamic acid esters)
[0107] Polyamic acid esters can be obtained by known methods, such as, for example, [I] a method of reacting a polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, and [III] a method of reacting a tetracarboxylic acid diester dihalogenate with a diamine.
[0108] (Synthesis of polyimide)
[0109] Polyimide can be obtained by ring-closing (imidizing) the above polyimide precursor. Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, or catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor.
[0110] The temperature at which the polyimide precursor is thermoimidized in solution is typically 100 to 400°C, preferably 120 to 250°C, and it is preferable to perform the process while removing water generated by the imidization reaction from the system.
[0111] Catalytic imidation of a polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring, preferably at -20 to 250°C, more preferably at 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 moles of the amic acid group, more preferably 2 to 20 moles, and the amount of the acid anhydride is preferably 1 to 50 moles of the amic acid group, more preferably 3 to 30 moles. Examples of basic catalysts include pyridine and triethylamine. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. The imidation rate by catalytic imidation can be controlled by adjusting the amount of catalyst, the reaction temperature, and the reaction time.
[0112] When recovering the polyimide precursor or polyimide produced from a reaction solution of a polyimide precursor or polyimide, the reaction solution can be precipitated by adding it to a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc.
[0113] The weight-average molecular weight (Mw) in polystyrene equivalent, measured by gel permeation chromatography (GPC) of the polyimide precursor and polyimide, is preferably 1,000 to 500,000 and more preferably 2,000 to 300,000. In addition, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) in polystyrene equivalent measured by GPC, is preferably 15 or less and more preferably 10 or less. By being within this molecular weight range, good orientation of the liquid crystal display device can be secured.
[0114] <End-level sachet>
[0115] In synthesizing the polyimide precursor or polyimide in the present invention, a polymer with terminal encapsulation may be synthesized using a suitable terminal encapsulator together with a tetracarboxylic acid derivative component containing tetracarboxylic acid dihydride or a derivative thereof, and a diamine component containing said diamine. The polymer with terminal encapsulation has the effect of improving the film hardness of the liquid crystal alignment film obtained by the coating film, and improving the adhesion between the sealant and the alignment film.
[0116] Examples of the polyimide precursor or the end of the polyimide in the present invention include amino groups, carboxyl groups, acid anhydride groups, or groups derived from the end encapsulating agent described below. Amino groups, carboxyl groups, and acid anhydride groups can be obtained by a conventional condensation reaction or by encapsulating the end using the end encapsulating agent described below.
[0117] As terminal encapsulators, for example, acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic acid anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl bicarbonate and diallyl bicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinate chloride; Examples include monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine; isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.
[0118] The usage ratio of the terminal encapsulant is preferably 0.01 to 20 moles per 100 moles of the total diamine components used, and more preferably 0.01 to 10 moles.
[0119] Liquid Crystal Alignment Agent
[0120] The liquid crystal alignment agent of the present invention comprises a polymer (A) and a polymer (B) and a crosslinkable compound (C) described below. In addition to the polymer (A) and the polymer (B), the liquid crystal alignment agent of the present invention may also contain other polymers. Examples of other polymers include polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivative, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate, etc.
[0121] Other polymers may be used alone or in combination of two or more types. The content ratio of other polymers is preferably 30 parts by mass or less, more preferably 1 to 25 parts by mass, and even more preferably 1 to 20 parts by mass, based on 100 parts by mass of the total polymers contained in the liquid crystal alignment agent.
[0122] A liquid crystal alignment agent is used to manufacture a liquid crystal alignment film and takes the form of a coating solution in order to form a uniform thin film. In the liquid crystal alignment agent of the present invention, it is also preferable that it be in the form of a coating solution containing the above-mentioned polymer component and an organic solvent.
[0123] The organic solvent contained in the above coating solution is not particularly limited as long as the polymer component is uniformly dissolved, and for example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactoamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, Examples include N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (these are collectively referred to as "both solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone are preferred. The content of the both solvent is preferably 20 to 99 mass% of the total solvent contained in the liquid crystal orientation agent, more preferably 20 to 90 mass%, and particularly preferably 30 to 80 mass%.
[0124] In addition, for the organic solvent contained in the liquid crystal alignment agent, it is preferable to use a mixed solvent in which a solvent (also called a co-solvent) is added to the solvent to improve the applicability or surface smoothness of the coating film when applying the liquid crystal alignment agent. Specific examples of the co-solvent used in combination are provided below, but are not limited thereto. The content of the co-solvent is preferably 1 to 80 mass% of the total solvent contained in the liquid crystal alignment agent, more preferably 10 to 80 mass%, and particularly preferably 20 to 70 mass%. The type and content of the co-solvent are appropriately selected according to the coating apparatus, coating conditions, coating environment, etc., of the liquid crystal alignment agent.
[0125] As co-solvents, for example, diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, Propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, 3-methyl methoxypropionate, 3-ethyl ethoxypropionate, 3-ethyl methoxypropionate, Examples include 3-propyl methoxypropionate, 3-butyl methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.
[0126] Among these, diisobutylcarbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.
[0127] Preferred combinations of solvents of both solvent and non-solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-dimethyllactoamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone and 3-ethyl ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and 3-ethyl ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 3-ethyl ethoxypropionate and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and 3-ethyl ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyllactoamide and ethylene glycol monobutyl ether, N,N-dimethyllactoamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether and Butyl cellosolve acetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyllactoamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and Dipropylene glycol monomethyl ether,N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and Diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutylcarbinol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and Diisobutyl ketone, N-ethyl-2-pyrrolidone and N,N-dimethyllactoamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and cyclohexyl acetate and diacetone alcohol cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether, N-methyl-2-pyrrolidone and cyclohexanone and Propylene glycol monomethyl ether,Tetramethylurea and 4-hydroxy-4-methyl-2-pentanone, tetramethylurea and propylene glycol diacetate, N,N-dimethylpropionamide and propylene glycol monobutyl ether, tetramethylurea and propylene glycol monobutyl ether, tetramethylurea and cyclohexanone and propylene glycol monomethyl ether, N,N-dimethylpropionamide and propylene glycol monomethyl ether, N,N-dimethylpropionamide and ethylene glycol monobutyl ether acetate, N,N-dimethylpropionamide and ethylene glycol monobutyl ether, tetramethylurea and propylene glycol monomethyl ether, N,N-dimethylpropionamide and cyclohexanone and diethylene glycol diethyl ether, N,N-diethylformamide and propylene glycol monomethyl ether, N,N-diethylformamide and Examples include 4-hydroxy-4-methyl-2-pentanone, N,N-diethylformamide, and propylene glycol monomethyl ether.
[0128] <Crosslinkable compound (C)>
[0129] The liquid crystal alignment agent of the present invention contains the crosslinkable compound (C). By adopting the above embodiment, the crosslinking reaction with the epoxy crosslinking agent proceeds during firing, thereby suppressing the thermoimidation reaction, that is, the thermoimidation reaction of the imide precursor contained in the polymer (B) component. Therefore, the liquid crystal alignment film obtained has a reduced imidized structure, so a liquid crystal alignment film is obtained that can reduce the generated charge in a short time while reducing the absolute value of the accumulated charge.
[0130] In the liquid crystal alignment agent of the present invention, the content of the crosslinkable compound (C) is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more preferably 1 to 15 parts by mass.
[0131] As a specific example of the above-mentioned crosslinking compound (C), N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-Bis(N,N-Diglycidylaminomethyl)benzene, 1,3,5-Tris(N,N-Diglycidylaminomethyl)cyclohexane, 1,3,5-Tris(N,N-Diglycidylaminomethyl)benzene, the following formula (E N -1) ∼ (E N Examples include compounds represented by -5). The crosslinking compound (C) may be used as a single type or in combination of two or more types.
[0132] [Chemical Formula 11]
[0133]
[0134] The liquid crystal alignment agent of the present invention may additionally contain components other than the polymer (A), (B) and the crosslinking compound (C) (hereinafter also referred to as additive components). Such additive components may include adhesion aids for increasing the adhesion between the liquid crystal alignment film and the substrate or between the liquid crystal alignment film and the sealant, compounds for increasing the strength of the liquid crystal alignment film other than the crosslinking compound (C) (hereinafter also referred to as other crosslinking compounds), dielectric or conductive materials for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film, imidization promoters, etc.
[0135] As other crosslinkable compounds mentioned above, there may be at least one crosslinkable compound selected from the group consisting of: a crosslinkable compound (C1) having an oxiranyl group other than the crosslinkable compound (C); a crosslinkable compound (C2) having at least one substituent selected from an oxetanyl group, a block isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl group, and an alkoxy group; and a crosslinkable compound (C3) having a polymerizable unsaturated group.
[0136] Specific examples of the above-mentioned crosslinking compound (C1) include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resin such as jER828 (manufactured by Mitsubishi Chemical), bisphenol F type epoxy resin such as jER807 (manufactured by Mitsubishi Chemical), hydrogenated bisphenol A type epoxy resin such as YX-8000 (manufactured by Mitsubishi Chemical), and YX6954BH30 (Mitsubishi Biphenyl backbone-containing epoxy resins such as those manufactured by Chemical Co., Ltd., phenol novolak-type epoxy resins such as EPPN-201 (manufactured by Nippon Hwayakusho), (o,m,p-)cresol novolak-type epoxy resins such as EOCN-102S (manufactured by Nippon Hwayakusho), triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Co., Ltd.), alicyclic epoxy resins such as Celoxide 2021P (manufactured by Daicel Chemical Industry Co., Ltd.), N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, In addition to tetrakis(glycidyloxymethyl)methane, examples include compounds described in paragraph
[0037] of Japanese Patent Publication No. Hei 10-338880 and compounds described in International Publication No. 2017 / 170483.
[0137] Specific examples of the above-mentioned crosslinkable compounds (C2) and (C3) include: compounds having two or more oxetanyl groups as described in paragraphs
[0170] to
[0175] of International Publication No. 2011 / 132751; compounds having a block isocyanate group such as Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosho Co.), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemical Co.); Compounds having an oxazoline group such as 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris(2-oxazolinyl-2)-benzene, epochose (manufactured by Nippon Catalytic Co.); compounds having a cyclocarbonate group as described in paragraphs
[0025] to
[0030] ,
[0032] of International Publication No. 2011 / 155577; Compounds having hydroxyl or alkoxy groups, such as n,n,n',n'-tetrakis(2-hydroxyethyl)adipoamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; Examples include glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-, 1,3-mixture), glycerin tri(meth)acrylate, glycerol 1,3-diglycerolato di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.
[0138] The above compound is an example of a crosslinkable compound, but is not limited thereto. For example, other components disclosed on pages 53
[0105] to 55
[0116] of International Publication No. 2015 / 060357 may be cited. In addition, two or more types of crosslinkable compounds may be combined.
[0139] In the liquid crystal alignment agent of the present invention, the content of crosslinkable compounds (C1) to (C3) is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of polymer components contained in the liquid crystal alignment agent, and more preferably 1 to 15 parts by mass.
[0140] The above adhesion aids include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, Examples of functional silane compounds include p-stylyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane. When using functional silane compounds, the content is preferably 0.1 to 30 parts by mass per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more preferably 0.1 to 20 parts by mass.
[0141] The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) is appropriately selected considering viscosity, volatility, etc., but is preferably in the range of 0.5 to 15 mass%, more preferably 1 to 10 mass%.
[0142] The particularly preferred range of solid content concentration varies depending on the method used when applying the liquid crystal alignment agent to the substrate. For example, in the case of the spinner method, a solid content concentration in the range of 1.5 to 4.5 mass% is particularly preferred. In the case of the printing method, it is particularly preferred to set the solid content concentration in the range of 3 to 9 mass%, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of the inkjet method, it is particularly preferred to set the solid content concentration in the range of 1 to 5 mass%, thereby setting the solution viscosity in the range of 3 to 15 mPa·s.
[0143] <Liquid crystal alignment layer and liquid crystal display element>
[0144] The liquid crystal alignment layer of the present invention is obtained from the liquid crystal alignment agent. The liquid crystal alignment layer of the present invention can be used for a horizontal alignment type or a vertical alignment type (VA type) liquid crystal alignment layer, but is a liquid crystal alignment layer preferred for a horizontal alignment type liquid crystal display device such as an IPS type or an FFS type. The liquid crystal display device of the present invention is equipped with the liquid crystal alignment layer. The liquid crystal display device of the present invention can be manufactured, for example, by a method including the following processes (1) to (3).
[0145] (1) Process of applying a liquid crystal alignment agent onto a substrate
[0146] The liquid crystal alignment agent of the present invention is applied to one surface of a substrate having a patterned transparent conductive film formed thereon by an appropriate coating method, such as a roll coater method, a spin coat method, a printing method, or an inkjet method. Here, the substrate is not particularly limited as long as it is a highly transparent substrate, and in addition to glass substrates and silicon nitride substrates, plastic substrates such as acrylic substrates or polycarbonate substrates may also be used. Furthermore, in the case of a reflective liquid crystal display device, if only one side of the substrate is used, an opaque material such as a silicon wafer may be used, and in this case, a light-reflecting material such as aluminum may be used for the electrode. In addition, when manufacturing an IPS or FFS type liquid crystal display device, a substrate having an electrode formed thereon consisting of a comb-patterned transparent conductive film or a metal film, and a counter substrate having no electrode formed thereon are used.
[0147] (2) Process of firing the coating
[0148] After applying the liquid crystal alignment agent, preheating (prebaking) is preferably performed first for purposes such as preventing the liquid of the applied liquid crystal alignment agent from stretching. The prebaking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The prebaking time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Additionally, it is preferable to perform a further heating (postbaking) process. The postbaking temperature is preferably 80 to 200°C, and more preferably 120 to 180°C. The postbaking time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The film thickness of the film formed in this way is preferably 5 to 300 nm, and more preferably 10 to 200 nm.
[0149] The film formed in the above process (1) or (2) can be used as is as a liquid crystal alignment film, but an alignment ability imparting treatment may be performed on the film. Examples of alignment ability imparting treatments include rubbing the film in a certain direction with a roll wound with a fabric made of fibers such as nylon, rayon, or cotton, and photoalignment treatment in which polarized or non-polarized radiation is irradiated onto the film.
[0150] In the photo-alignment treatment, ultraviolet and visible light, including light with wavelengths of 150 to 800 nm, may be used as the radiation irradiated onto the coating film. When the radiation is polarized, it may be linearly polarized or partially polarized. Furthermore, when the radiation used is linearly polarized or partially polarized, irradiation may be performed in a direction perpendicular to the substrate surface, in an oblique direction, or in a combination thereof. When irradiating with non-polarized radiation, the direction of irradiation is oblique.
[0151] (3) Process for manufacturing liquid crystal cells
[0152] As described above, two substrates having liquid crystal alignment layers formed thereon are prepared, and liquid crystal is placed between the two substrates arranged opposite each other. Specifically, the following two methods may be used. In the first method, two substrates are first arranged opposite each other with a gap (cell gap) interposed so that each liquid crystal alignment layer faces the other. Subsequently, the periphery of the two substrates is bonded using a sealant, and a liquid crystal composition is injected and filled into the cell gap partitioned by the substrate surface and the sealant, and then the injection hole is sealed after contact with the film surface.
[0153] In addition, the second method is a technique called the ODF (One Drop Fill) method. For example, a UV-curable sealant is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film is formed, and a liquid crystal composition is dropped onto several predetermined points on the surface of the liquid crystal alignment film. Then, the other substrate is laminated so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread widely over the entire surface of the substrate and brought into contact with the film surface. Subsequently, the sealant is cured by irradiating ultraviolet light onto the entire surface of the substrate. In either method, it is additionally preferable to remove the flow alignment during liquid crystal filling by heating the liquid crystal composition used to a temperature at which it takes on an isotropic phase, and then slowly cooling it to room temperature.
[0154] In addition, when rubbing treatment is performed on the coating film, the two substrates are arranged facing each other so that the rubbing direction in each coating film is at a predetermined angle to each other, for example, orthogonal or antiparallel.
[0155] As a sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer may be used. As for the liquid crystal composition, there are no particular limitations, and compositions containing at least one liquid crystal compound (liquid crystal molecule) may include a liquid crystal composition exhibiting a nematic phase (hereinafter also referred to as a nematic liquid crystal), a liquid crystal composition exhibiting a smectic phase, and a smectic liquid crystal composition, among which a nematic liquid crystal is preferred. In addition, various liquid crystal compositions having positive or negative dielectric anisotropy may be used. Furthermore, hereinafter, a liquid crystal composition having positive dielectric anisotropy is referred to as a positive liquid crystal, and a liquid crystal composition having negative dielectric anisotropy is referred to as a negative liquid crystal.
[0156] The above liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxyl group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocyclic ring, a cycloalkane, a cycloalkene, a steroid backbone, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid sites (methogen backbones) that exhibit liquid crystallization within the molecule (e.g., two rigid biphenyl structures, or a bimethogen compound in which a terphenyl structure is connected to an alkyl group).
[0157] In addition, the liquid crystal composition may further contain additives to improve liquid crystal orientation. Such additives may include photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck & Co., Ltd.); antioxidants; ultraviolet absorbers; pigments; antifoaming agents; polymerization initiators; or polymerization inhibitors.
[0158] Examples of positive liquid crystals include Merck's ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, or MLC-7081.
[0159] Examples of negative liquid crystals include Merck's MLC-6608, MLC-6609, MLC-6610, MLC-7026, or MLC-7026-100.
[0160] In addition, as a liquid crystal containing a compound having a polymerizable group, Merck's MLC-3023 can be cited.
[0161] In addition, a liquid crystal display device can be obtained by laminating a polarizer to the outer surface of a liquid crystal cell as needed. Examples of polarizers laminated to the outer surface of a liquid crystal cell include a polarizer in which a polarizing film called an "H film," which absorbs iodine while polyvinyl alcohol is stretched and oriented, is sandwiched between cellulose acetate protective films, or a polarizer consisting of the H film itself.
[0162] The liquid crystal alignment film of the present invention can be applied to various uses in addition to the liquid crystal alignment film for the above purposes, and for example, it can be used as a liquid crystal alignment film for a phase difference film, a liquid crystal alignment film for a scanning antenna or a liquid crystal array antenna, or a liquid crystal alignment film for a transmission scattering type liquid crystal light-diffusing element. Furthermore, it can be used for uses other than liquid crystal alignment films, for example, a protective film (e.g., a protective film for a color filter), a spacer film, an interlayer insulating film, an anti-reflective film, a wiring coating film, an antistatic film, and a motor insulating film (a gate insulating film for a flexible display).
[0163] The liquid crystal display element of the present invention can be effectively applied to various devices, and can be used in various display devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays.
[0164] [Example]
[0165] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited thereto. The abbreviations of compounds and methods for measuring each characteristic described below are as follows.
[0166] (Diamine)
[0167] [Chemical Formula 12]
[0168]
[0169] (Tetracarboxylic acid 2 anhydride)
[0170] [Chemical Formula 13]
[0171]
[0172] (Cross-linking compound)
[0173] [Chemical Formula 14]
[0174]
[0175] (Adhesion aid)
[0176] [Chemical Formula 15]
[0177]
[0178] (End sachet)
[0179] [Chemical Formula 16]
[0180]
[0181] (Organic solvent)
[0182] NMP: N-methyl-2-pyrrolidone
[0183] GBL: γ-butyrolactone
[0184] BCS: Butyl cellosolve (ethylene glycol monobutyl ether)
[0185] <Measurement of Imide Conversion Rate>
[0186] 20 mg of polyimide powder was placed in an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku Co., Ltd.)), deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) (0.53 mL) was added, and the mixture was completely dissolved by applying ultrasound. The proton NMR of this solution at 500 MHz was measured using an NMR detector (JNW-ECA500) (manufactured by Nihon Denshi Datum Co., Ltd.). The imidation rate was determined by the following formula using the peak integration value of a proton originating from a structure that does not change before and after imidation as a reference proton, and the peak integration value of this proton and the proton peak integration value originating from the NH group of the amic acid appearing around 9.5 ppm to 10.0 ppm.
[0187] Imidization rate (%) = (1 - α·x / y) × 100
[0188] In the above formula, x is the peak integration value of the NH group of the amic acid, y is the peak integration value of the reference proton, and α is the ratio of the number of reference protons to one NH group proton of the amic acid in the case of polyamic acid (imidization rate 0%).
[0189] [Synthesis of Polymers]
[0190] <Synthesized Example 1>
[0191] In a 300 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 8.60 g (35.2 mmol) of DA-2, 5.34 g (9.59 mmol) of DA-4, and 7.65 g (19.1 mmol) of DA-3 were weighed, and NMP was added to achieve a solid content of 12 mass%, and dissolved by stirring while introducing nitrogen. While stirring the diamine solution under water cooling, 9.32 g (41.6 mmol) of CA-1 was added, and additionally NMP was added to achieve a solid content of 15 mass%, and the mixture was stirred at 40 °C for 3 hours under a nitrogen atmosphere. In addition, 2.82 g (14.3 mmol) of CA-2 was added, and NMP was additionally added to achieve a solid content concentration of 15 mass%, stirred at 23 °C for 4 hours under a nitrogen atmosphere, and a polyamic acid solution (PAA-A-1) was obtained.
[0192] 80.0 g of the polyamic acid solution (PAA-A-1) obtained above was aliquoted into a 300 mL Erlenmeyer flask containing a stirrer, 70.0 g of NMP, 6.97 g of acetic anhydride, and 1.80 g of pyridine were added, stirred at room temperature for 30 minutes, and then reacted at 55 °C for 3 hours. The reaction solution was added to 560 g of methanol, and the resulting precipitate was filtered and separated. After washing the precipitate with methanol, it was dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide was 75%.
[0193] 9.00 g of the polyimide powder was taken into a 300 mL Erlenmeyer flask containing a stirrer, 36.0 g of NMP was added, and the mixture was dissolved by stirring at 50 °C for 20 hours to obtain a solution of polyimide (PI-A-1) with a solid content concentration of 20 mass%.
[0194] Table 1 shows the types and amounts of diamine and tetracarboxylic acid derivatives used when preparing the solution of the polyimide (PI-A-1) obtained in Synthesis Example 1, the presence or absence of E-1, and the imidization rate.
[0195] <Synthesized Example 2>
[0196] In a 200 mL 4-neck flask equipped with a stirring device and a nitrogen inlet tube, 8.04 g (40.2 mmol) of DA-1, 4.36 g (10.9 mmol) of DA-3, and 12.2 g (21.9 mmol) of DA-4 were weighed, and 98.4 g of NMP was added and dissolved by stirring while introducing nitrogen. While stirring the diamine solution under water cooling, 9.40 g (47.4 mmol) of CA-3 was added, and an additional 37.6 g of NMP was added, and the mixture was stirred at 50 °C for 2 hours under a nitrogen atmosphere. In addition, 4.65 g (23.7 mmol) of CA-2 was added, and 18.6 g of NMP was added, and the mixture was stirred at 23 °C for 2 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (PAA-A-2).
[0197] 100 g of the solution of the polyamic acid obtained was taken into a 200 mL Erlenmeyer flask containing a stirrer, 1.24 g (5.68 mmol) of E-1 was added, and the mixture was stirred at 40 °C for 15 hours to obtain a solution of terminally encapsulated polyamic acid (PAA-A-3).
[0198] 100 g of the above solution of (PAA-A-3) was aliquoted into a 200 mL Erlenmeyer flask containing a stirrer, and 66.7 g of NMP, 14.2 g of acetic anhydride, and 4.70 g of pyridine were added. The mixture was stirred at room temperature for 30 minutes, and then reacted at 60 ℃ for 4 hours. This reaction solution was added to 650 g of methanol, and the resulting precipitate was filtered and separated. After washing the precipitate with methanol, it was dried under reduced pressure at 80 ℃ to obtain a polyimide powder (imidization rate: 89%).
[0199] In addition, 9.60 g of the powder of this polyimide was taken into a 100 mL Erlenmeyer flask containing a stirrer, 70.4 g of NMP was added, and the mixture was dissolved by stirring at 70 °C for 24 hours to obtain a solution of polyimide (PI-A-2) with a solid content concentration of 12 mass%.
[0200] Table 1 shows the types and amounts of diamine and tetracarboxylic acid derivatives used when preparing the solution of the polyimide (PI-A-2) obtained in Synthesis Example 2, the presence or absence of E-1, and the imidization rate.
[0201] <Synthesized Example 3>
[0202] 38.26 g (96.0 mmol) of DA-3 and 44.41 g (224.0 mmol) of DA-8 were weighed into a 1 L 4-neck flask equipped with a stirring device and a nitrogen inlet tube, and 606.2 g of NMP was added to achieve a solid content of 12 mass%, and the mixture was dissolved by stirring while introducing nitrogen. While stirring the diamine solution under water cooling, 48.32 g (246.4 mmol) of CA-2 and 166.1 g of NMP were added, and the mixture was stirred for 2 hours under water cooling in a nitrogen atmosphere. In addition, 18.83 g (64.0 mmol) of CA-4 was added, and 76.6 g of NMP was added, stirred at 50 °C for 15 hours under a nitrogen atmosphere, and a solution of polyamic acid (PAA-B-1) with a solid content of 15 mass% was obtained.
[0203] <Synthesized Examples 4–7>
[0204] Solutions of polyamic acids (PAA-B-2) to (PAA-B-5) shown in Table 2 below were obtained by using diamine and tetracarboxylic acid derivatives shown in Table 2 below, using the same organic solvent as in Synthesis Example 3 for each, and carrying out the process in the same order as in Synthesis Example 3.
[0205] <Synthesized Example 8>
[0206] 39.65 g (200.0 mmol) of DA-8 and 42.66 g (200.0 mmol) of DA-5 were weighed into a 1 L 4-neck flask equipped with a stirring device and a nitrogen inlet tube, and 603.6 g of NMP was added to achieve a solid content of 12% mass, and dissolved by stirring while introducing nitrogen. While stirring the diamine solution under water cooling, 74.52 g (380.0 mmol) of CA-2 and 285.1 g of NMP were added, and the mixture was stirred for 4 hours under water cooling in a nitrogen atmosphere to obtain a solution of polyamic acid (PAA-B-6) with a solid content of 15 mass%.
[0207] Table 2 shows the types and amounts of diamine and tetracarboxylic acid derivatives used when preparing the solution of polyamic acid (PAA-B-6) obtained in Synthesis Example 8.
[0208]
[0209]
[0210] [Preparation of Liquid Crystal Orientation Agent]
[0211] <Examples 1–4, Comparative Examples 1–5>
[0212] In a 200 mL Erlenmeyer flask, solutions of polyamic acid and polyimide obtained in Synthesis Examples 1 to 8 were each weighed and taken in amounts shown in Table 3 below. While stirring, NMP, GBL, NMP solution containing 10 mass% crosslinking compound, GBL solution containing 1 mass% adhesion aid, and BCS were added in that order, and by stirring at room temperature for 2 hours, liquid crystal orientation agents (1) to (9) were obtained.
[0213]
[0214] [Manufacturing of FFS-type liquid crystal display devices]
[0215] A liquid crystal cell having the configuration of a Fringe Field Switching (FFS) mode liquid crystal display element was manufactured.
[0216] First, a substrate with attached electrodes was prepared. The substrate was a glass substrate with dimensions of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an ITO electrode having a beta pattern was formed as the first layer, constituting a counter electrode, and on the first layer counter electrode, a SiN (silicon nitride) film deposited by the CVD method was formed as the second layer. The second layer SiN film used had a thickness of 500 nm and functioned as an interlayer insulating film. On the second layer SiN film, a comb-shaped pixel electrode formed by patterning an ITO film was disposed as the third layer, and two pixels, a first pixel and a second pixel, were formed. The size of each pixel was 10 mm in height and approximately 5 mm in width. At this time, the first layer counter electrode and the third layer pixel electrode were electrically insulated by the action of the second layer SiN film.
[0217] The pixel electrode of the third layer has a comb shape in which multiple electrode elements with a width of 3 μm, which are bent at an internal angle of 160° in the central part, are arranged parallel to each other at a distance of 6 μm, and one pixel has a first region and a second region bordered by a line connecting the bent parts of the multiple electrode elements.
[0218] When comparing the first and second regions of each pixel, the formation direction of the electrode elements of the pixel electrodes constituting them was different. That is, based on the direction connecting the curved portions of the plurality of electrode elements, the electrode elements of the pixel electrodes in the first region of the pixel were formed to form an angle of 80° clockwise, and the electrode elements of the pixel electrodes in the second region of the pixel were formed to form an angle of 80° counterclockwise. In other words, the first and second regions of each pixel were configured such that the direction of rotational movement (in-plane switching) within the substrate surface of the liquid crystal induced by the application of voltage between the pixel electrode and the counter electrode was opposite to each other.
[0219] Next, liquid crystal alignment agents (1) to (9) were each filtered through a filter with a pore size of 1.0 μm and then applied to the prepared electrode-attached substrate by spin coating. After drying on a hot plate at 80°C for 5 minutes, the film was fired in an IR oven at 150°C for 20 minutes to obtain a polyimide film with a thickness of 60 nm. The polyimide film was rubbed and aligned with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm, rubbing direction: 180° relative to the direction connecting the curved portions of the plurality of electrode elements of the third layer pixel electrode), then cleaned by ultrasonic irradiation in pure water for 1 minute and removed water droplets with an air blow. Afterwards, the substrate was dried at 80°C for 15 minutes to obtain a liquid crystal alignment film attached substrate. Additionally, as a counter substrate, a glass substrate having a columnar spacer with a height of 4 μm and an ITO electrode formed on its back surface was treated in the same manner as above to obtain a liquid crystal alignment film attached substrate with an alignment treatment. These two liquid crystal alignment film attached substrates were paired, and a sealant (XN-1500T manufactured by Mitsui Chemical Co., Ltd.) was printed on one substrate in a shape leaving a liquid crystal injection port, and the other substrate was attached with the liquid crystal alignment film surface facing each other and the rubbing direction being antiparallel. Afterwards, a heat treatment was performed at 150°C for 60 minutes to cure the sealant, thereby producing an empty cell with a cell gap of 4 μm. A negative liquid crystal MLC-7026-100 (manufactured by Merck) was injected into this empty cell by vacuum injection, and the injection port was sealed to obtain an FFS type liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120°C for 1 hour, left at 23°C overnight, and then used to evaluate liquid crystal alignment.
[0220] [Manufacturing of Liquid Crystal Cells for Voltage Maintenance Rate Measurement]
[0221] Liquid crystal alignment agents (1) to (9) were each filtered through a 1.0 μm filter and then coated by spin coating onto an electrode-attached substrate (a glass substrate with dimensions of 30 mm x 40 mm and a thickness of 1.1 mm, on which a rectangular ITO electrode with a width of 10 mm x a length of 40 mm and a thickness of 35 nm was formed). After drying on a hot plate at 50°C for 5 minutes, the substrate was fired in an IR oven at 150°C for 20 minutes to form a film with a thickness of 60 nm, thereby obtaining a liquid crystal alignment film-attached substrate. After rubbing the liquid crystal alignment film with a rayon spring (Yoshikawa Chemical Co., Ltd. YA-20R) for alignment (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm), cleaning was performed by ultrasonic irradiation in pure water for 1 minute, water droplets were removed by air blowing, and then dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal alignment film attached.
[0222] Two substrates with the liquid crystal alignment film attached as described above were prepared. A 4 μm spacer was spread on the liquid crystal alignment film surface of one of the substrates, and a sealant (XN-1500T manufactured by Mitsui Chemicals) was printed over it. The other substrate was attached with the rubbing direction reversed and the film surfaces facing each other, and then a heat treatment was performed at 150°C for 60 minutes to cure the sealant and manufacture an empty cell. A negative-type liquid crystal MLC-7026-100 (manufactured by Merck) was injected into this empty cell by a reduced-pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. Subsequently, the obtained liquid crystal cell was heated at 120°C for 1 hour and left overnight at 23°C to obtain a liquid crystal cell for measuring voltage retention rate.
[0223] [evaluation]
[0224] 1. Evaluation of orientation stability by long-term AC drive
[0225] A liquid crystal cell manufactured in the above FFS method liquid crystal display device was used.
[0226] Using this liquid crystal cell, an AC voltage of ±10 V was applied at a frequency of 60 Hz for 168 hours on a high-brightness backlight (light source: LED, brightness: 20000 cd / m²) with a surface temperature of 50 ℃. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and the cell was left at room temperature for one day.
[0227] After leaving it undisturbed, the liquid crystal cell was placed between two polarizing plates arranged so that their polarization axes were orthogonal, and the backlight was turned on in a state where no voltage was applied. The arrangement angle of the liquid crystal cell was then adjusted so that the brightness of the transmitted light was minimized. Then, the rotation angle Δ was calculated as the angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel becomes darkest to the angle at which the first region becomes darkest. In the same way, the same angle Δ was calculated for the second pixel by comparing the second region and the first region.
[0228] The stability of liquid crystal alignment was evaluated by defining it as "good" when the angle Δ is less than 0.4° and "poor" when the angle Δ is 0.4° or more. The evaluation results are shown in Table 4.
[0229] 2. Measurement of the relaxation time of accumulated charge
[0230] A liquid crystal cell manufactured in the same manner as the above (manufacturing of a liquid crystal display element of the FFS method) was installed between two polarizing plates arranged so that their polarization axes are orthogonal, and with the pixel electrode and the counter electrode short-circuited to be at the same potential, an LED backlight was irradiated from below the two polarizing plates, and the angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured above the two polarizing plates was minimized. Next, an AC voltage of frequency 60 Hz was applied to this liquid crystal cell, and the VT curve (voltage-transmittance curve) was measured, and the AC voltage at which the relative transmittance becomes 23% was calculated as the driving voltage.
[0231] In the afterimage evaluation, the liquid crystal cell was driven by applying an AC voltage of 60 Hz at a frequency where the relative transmittance was 23%, while simultaneously applying a DC voltage of 1 V and driving for 120 minutes. After that, only the application of the DC voltage was stopped, and the cell was driven for an additional 15 minutes using only the AC voltage.
[0232] It was evaluated by defining it as “good” if the relative transmittance was reduced to 25% or less by 10 minutes from the time the application of DC voltage was stopped, and as “poor” if it took more than 10 minutes for the relative transmittance to decrease to 25% or less.
[0233] In addition, the afterimage evaluation according to the method described above was performed under temperature conditions where the liquid crystal cell temperature was 40 ℃. The evaluation results are shown in Table 4.
[0234] 3. Evaluation of Charge Accumulation by AC Driving
[0235] A liquid crystal cell manufactured in the same manner as the above (manufacturing of a liquid crystal display element of the FFS method) was installed between two polarizing plates arranged so that their polarization axes are orthogonal, and with the pixel electrode and the counter electrode short-circuited to be at the same potential, an LED backlight was irradiated from below the two polarizing plates, and the angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured above the two polarizing plates was minimized. Next, an AC voltage of frequency 60 Hz was applied to this liquid crystal cell, and the VT curve (voltage-transmittance curve) was measured, and the AC voltage at which the relative transmittance becomes 23% was calculated as the driving voltage.
[0236] In the afterimage evaluation, an AC voltage of 60 Hz at which the relative transmittance is 100% was applied to drive the liquid crystal cell for 60 minutes. Afterward, an AC voltage with a relative transmittance of 23% was applied, and while sweeping the DC voltage, the applied voltage that minimizes the flickering of the display was measured. The absolute value of this applied voltage that minimizes the flickering of the display was defined as the charge accumulation amount, and the evaluation was performed by defining it as "defective" if this value exceeded 100 mV and as "good" if it was 100 mV or less.
[0237] In addition, the afterimage evaluation according to the method described above was performed under temperature conditions where the liquid crystal cell temperature was 40 ℃. The evaluation results are shown in Table 4.
[0238] 4. Evaluation of Voltage Maintenance Rate Stability Under Backlight
[0239] A voltage of 1 V was applied to the liquid crystal cell for measuring voltage retention rate described above at a temperature of 60 ℃ for 60 μsec, and the voltage after 167 msec was measured to calculate how long the voltage could be maintained as the voltage retention rate. This was set as the initial voltage retention rate.
[0240] Next, as a backlight tolerance test, this liquid crystal cell was left for 168 hours under irradiation of a high-brightness backlight (light source: LED, brightness: 20,000 cd / m²) with a surface temperature of 50°C. The voltage retention rate of this liquid crystal cell was measured in the same manner as above. This is taken as the voltage retention rate after the tolerance test.
[0241] The backlight tolerance of the voltage maintenance rate was evaluated by determining that the value obtained by subtracting the value after the tolerance test from the initial value was "good" if it was less than 5%, and "poor" if it was 5% or more. The evaluation results are shown in Table 4.
[0242] 5. Evaluation of rubbing resistance
[0243] Liquid crystal alignment agents (1) to (9) were each applied to an ITO substrate by spin coating. After drying on a hot plate at 60°C for 1 minute and 30 seconds, the film was fired in an IR oven at 150°C for 20 minutes to form a film with a thickness of 100 nm. Afterward, the liquid crystal alignment film was rubbed twice consecutively with a rayon cloth (Yoshikawa Chemical Co., Ltd. YA-20R) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.5 mm). When observing the surface of the film with a confocal laser microscope, a film with scratches was defined as "defective" and a film without scratches was defined as "good" for evaluation. The evaluation results are shown in Table 4.
[0244] For liquid crystal display devices using each liquid crystal alignment agent of Examples 1 to 4 and Comparative Examples 1 to 5 above, the evaluation results performed as described above are shown in Table 4 below.
[0245]
[0246] Industrial applicability
[0247] The liquid crystal alignment agent of the present invention is useful for forming a liquid crystal alignment film in a wide range of liquid crystal display devices, such as IPS driving methods or FFS driving methods.
[0248] In addition, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2021-078636 filed on May 6, 2021 are incorporated herein by reference and accepted as the disclosure of the specification of the present invention.
Claims
Claim 1 A liquid crystal orientation agent characterized by containing the following polymer (A), polymer (B), and crosslinkable compound (C). Polymer (A): a diamine represented by the following formula (d0) and the following formula (d D Polyimide polymer (B): "HN(R)-Y D' -N(R)-H」(Y D' represents a divalent organic group having a group "-N(D')-" within the molecule (D' represents a protecting group that is detached by heating and replaced by a hydrogen atom). R is represented by the formula (d D It has the same meaning as R of ).) Diamine represented as (d D'B ) and the following expression (d B Diamine represented by ) (wherein diamine (d D'B A polyimide precursor that is a reaction product of a diamine component and a tetracarboxylic acid derivative component, wherein the polyimide precursor does not have an imide ring structure, and additionally, if the tetracarboxylic acid derivative component of the polymer (B) has a cyclobutane ring structure as a partial structure, the cyclobutane ring does not have a substituent. Crosslinkable compound (C): the following formula (E n Epoxy compounds represented by ). (In formula (d0), the two Ars each independently represent a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom on the ring may be substituted with a monovalent group. o -O-(-Ar'-O-) n - (n is an integer from 0 to 3. Ar' represents a divalent benzene ring or a biphenyl structure, and any hydrogen atom on the ring may be substituted with a monovalent group. If there are multiple Ar' groups, the multiple Ar' groups may be identical or different.), -(CH2) n - (n is an integer from 2 to 18), or that -(CH2) n - Represents a group in which at least a portion of the -CH2- is substituted with any one of -O-, -C(=O)- or -OC(=O)-. Formula (d D ) Among, Y D represents a divalent organic group having a group "-N(D)-" (D represents a protecting group that is detached by heating and replaced by a hydrogen atom) within the molecule. Formula (d0) and Formula (d D Among ), multiple Rs each independently represent a hydrogen atom or a monovalent organic group. (Y B ... represents a divalent organic group satisfying the following conditions (1) and (2). R has the same meaning as R in the above formula (d0).) Condition (1): It does not have a nitrogen atom-containing structure selected from the group consisting of a complex ring containing a nitrogen atom and a secondary or tertiary amino group (except for amino groups derived from the group "-N(D')-" (D' represents a protecting group that is detached by heating and replaced by a hydrogen atom). Condition (2): It does not have a side chain with 6 or more carbon atoms. (a is an integer from 2 to 4, and R a is an organic group of a, and the bonding sites with a number of N atoms are aliphatic carbon atoms. Claim 2 A liquid crystal orientation agent according to claim 1, wherein the imidization rate of the polyimide in the polymer (A) is 10 to 100%. Claim 3 In claim 1, in the polymer (B), the diamine component is of the following formula (d M A liquid crystal alignment agent containing a diamine represented by ). (L M represents a single bond, -CH2-, -CO-, -O-, or -C(CH3)2-. L M ' is, single bond or -(CH2) m - Represents (m is an integer from 1 to 2). Ar M Silver represents a divalent benzene ring, and any hydrogen atom on the ring may be replaced with a monovalent group. Ar M If this plural exists, the plural Ar M may be identical or different. Multiple Rs each independently represent a hydrogen atom or a monovalent organic group. n is an integer from 0 to 1.) Claim 4 A liquid crystal alignment agent according to claim 1, wherein the content of the diamine represented by the formula (d0) is 50 to 95 mol% with respect to the total component of the diamine component used in the manufacture of the polymer (A). Claim 5 In claim 1, the above formula (d D A liquid crystal alignment agent in which the content of the diamine represented by ) is 5 to 50 mol% relative to the total component of the diamine component used in the manufacture of polymer (A). Claim 6 A liquid crystal orientation agent according to claim 1, wherein the tetracarboxylic acid derivative component used in the manufacture of the polymer (A) contains an acyclic aliphatic tetracarboxylic acid dihydride, alicyclic tetracarboxylic acid dihydride, aromatic tetracarboxylic acid dihydride, or a derivative thereof. Claim 7 A liquid crystal orientation agent according to claim 6, wherein the tetracarboxylic acid derivative component used in the manufacture of polymer (A) contains a tetracarboxylic acid dihydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure. Claim 8 In claim 1, the diamine represented by formula (d0) is 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, a compound represented by the following formulas (d0-1) to (d0-10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, A liquid crystal orientation agent, at least one diamine selected from the group consisting of 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. Claim 9 In claim 1, the above formula (d D The diamine represented by ) is an aromatic diamine having one aromatic ring within the molecule, wherein at least one of any hydrogen atoms on the aromatic ring is substituted with a monovalent group having the group "-N(D)-" (d n1 ), or an aromatic diamine having two aromatic rings within the molecule, wherein the two aromatic rings are single bonds, -CH2-, -C(CH3)2-, -O-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D"), -NR- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D"), an alkylene group having 2 to 20 carbon atoms, and any -CH2- of the alkylene group is -O-, -Si(CH3)2-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a group "-D") or a divalent group selected from the group consisting of a divalent group substituted with -NR- (R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D") (L n As an aromatic diamine connected by ), (i) any hydrogen atom on the aromatic ring is substituted with a monovalent group having "-N(D)-", or (ii) said divalent group (L n ) An aromatic diamine satisfying at least one of the conditions having this group "-N(D)-" (d n2 ) Phosphorus, liquid crystal alignment agent. Claim 10 A liquid crystal alignment agent according to claim 1, wherein the content ratio of the polymer (A) and the polymer (B) is 10 / 90 to 90 / 10 in mass ratio of [polymer (A)] / [polymer (B)]. Claim 11 In claim 1, the crosslinking compound (C) comprises N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-Bis(N,N-Diglycidylaminomethyl)benzene, 1,3,5-Tris(N,N-Diglycidylaminomethyl)cyclohexane, 1,3,5-Tris(N,N-Diglycidylaminomethyl)benzene, and the following formula (E N -1) ∼ (E N A liquid crystal orientation agent, at least one selected from the group consisting of compounds represented by -5). Claim 12 A liquid crystal orientation agent according to claim 1, further comprising a crosslinkable compound other than the crosslinkable compound (C) and / or an adhesion aid. Claim 13 A liquid crystal alignment film obtained from a liquid crystal alignment agent described in any one of claims 1 to 12. Claim 14 In claim 13, a liquid crystal alignment film that is horizontally aligned. Claim 15 A liquid crystal display element having a liquid crystal alignment layer as described in claim 13.
Citation Information
Patent Citations
Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display device using same
WO2020158818A1
Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element using same
WO2019065646A1
Liquid crystal alignment treatment agent, liquid crystal alignment film, and liquid crystal display device
WO2020175561A1